Sweet病に合併した網膜血管炎の1例

Retinal vasculitis associated with Sweet syndrome: A case report

要約　目的：Sweet病は感染症・自己免疫疾患・悪性腫瘍・薬剤使用など，多様な因子に伴って発症するが，後眼部合併症は稀である。Sweet病に網膜血管炎を合併した1例を報告する。

症例：27歳，女性。発熱と上半身の有痛性膿痂疹が出現し，当院皮膚科でSweet病と診断されプレドニゾロン内服を開始された。2週間後に右眼霧視を自覚し，当科を紹介受診した。

所見：初診時，両眼とも矯正視力は1.5，眼圧は6mmHgであり，両側とも前房炎症細胞はなく，周辺部網膜に滲出斑が散在していた。光干渉断層計では両眼の傍中心窩内層構造が不明瞭化していた。蛍光眼底造影では両眼の周辺部網膜静脈と傍中心窩毛細血管から蛍光色素漏出を認めた。Sweet病に伴う両眼網膜血管炎と診断し，ベタメタゾン点眼を開始した。初診1か月後に左眼に黄斑浮腫が出現し，テノン囊下トリアムシノロン注射（STTA）を実施したところ改善した。初診2か月後にプレドニゾロン内服を終了した。4か月後に左眼視力低下を自覚したため，再度STTAを実施したところ改善した。初診5か月後に両眼の眼圧上昇のためベタメタゾン点眼を終了し，初診20か月後まで所見の著明な増悪は認めない。

結論：Sweet病に伴う網膜血管炎は非常に幅広い臨床像をとり，眼所見のみではBehçet病との鑑別は困難なことがある。網膜血管炎の診療においては，Sweet病および背景因子の可能性も念頭に置き，皮疹に注意して積極的に全身検索を実施するべきである。

Abstract　Purpose：Sweet's disease develops due to various factors such as infections, autoimmune diseases, malignant neoplasms, and drug use. However, ocular complications in posterior segments are rare. Here we report a case of Sweet's disease with retinal vasculitis.

Case：A 27-year-old woman developed fever and painful impetigo on the upper body, that was diagnosed as Sweet's disease by our hospital's dermatology department. Oral prednisolone was intoduced. Two weeks later, she noticed blurred vision of the right eye and was referred to our department.

Findings：In the initial examination, her best-corrected visual acuity was 1.5, and the bilateral intraocular pressure was 6 mmHg. No anterior chamber inflammatory cells were found, and scattered exudates were noted in the peripheral retina. Optical coherence tomography showed obscured bilateral parafoveal structure of the inner retina. Fluorescein fundus angiography revealed bilateral fluorescence leakage from the peripheral retinal veins and parafoveal vessels. She was diagnosed with bilateral retinal vasculitis associated with Sweet's disease and prescribed betamethasone eye drops. One month after the first visit, macular edema developed in the left eye, which improved after sub-Tenon's triamcinolone acetonide injection（STTA）. However, she stopped taking the oral prednisolone 2 months after the first visit；4 months later, she noticed blurred vision of the left eye. She underwent STTA again, which improved the left visual acuity. Five months after her first visit, the betamethasone eye drops were discontinued due to increased intraocular pressure, and no significant worsening was observed until 20 months after her first visit.

Conclusion：Retinal vasculitis associated with Sweet's disease has a very wide range of clinical manifestations, and it is difficult to differentiate it from Behçet's disease based on ocular findings alone. In casaes of retinal vasculitis, the possibility of Sweet's disease should be considered, and a full-body examination should be performed to detect skin involvement.